Control device for cutting machines



B. F. STOWELL.

CONTROL DEVICE FOR CUTTING MACHINES.

- I APPLICATION FILED DEC. 20, I920. 1,414,230.

Patented Apr. 25, 1922.

B. F. STOWELL. comnowawcs ron CUTTING.MACHINES.

APPLICATION FILED DEC.20..1920.

Patent ed Apr. 25, 1922.

B. F. STOWELL. CONTROL DEVICE FOR CUTTING MACHINES.

APPLICATION FILED DEC. 20,1920.

Patented Apr. 25, 1922.

3 SHEETS'-SIIEET 3.

lllnllllllllu well (Din.

' UNITED; STATES .FATENT- OFFICE BYRON F. srrownnnor SPRINGFIEL ,MAssAo UsETTs, AssIGnoR TOHM'ETAL saw" AND MACHINE oo.',*-'I1\To. 0F SPRINGFIELD,MASSACHUSETTS, A ooitronA'rronor r MASSACHUSETTS;

' contract. iinvion non confirms m;

To ZZZ-Z whomit may] concern Be it known that I, BYR0N "Which the following-is a 'specifi'cat'ion.

* 'Th-is inventionyrelates to power cutting machlnes ncluding sawing machln'es employing" an endless band saw as the cutting 'instrumentality. V L V l In cutting machines of the kind in 'WlllCll I the tool is-moved' toward the work, and especiallyinmetal sawing machines" of asuc-v 'cess'fu'l type in which an endless band saw blade is driven in a relatively heavy frame mounted formotion ina downward direction past a suitable worksuppOrt-to'feed the edge of the saw into the work, itisusual to permit an unbalancedportion of'the 'weight of thepivoted vframe-to measure the Y pressure on the saw for feeding the "saw through the work. It is desirable automatically tolimit the descent ofthe frame todetermine'the depth of cut, or to "prevent filjr- "ther descent after the saw has passed :or replacement of thework. l his'notonly through the work when used for cutting-off operations. Otherwise the running saw might strike the work'support or other portion of the machine frame,-and cause injury or breakage ifthe operator is inattentive.

The saw. frame as usually arrang'ed must-be,

raised byhand after the cornp'letion of one sawing operation to permit the adjustment Iconsumesl'the time and requires the attene l tion of the operatorfbut when'the framereimproved type forstopping the downwardmains-in its lowered-position after the op?- i era'tion is finished, the operatoroften is unaware of the completionof. theoperation untiliafter the lapse 'ofconsiderable time,thus

wasting-thetime of the machine. a

Onev object of the-Y present invention is. to provide automaticallyzactlng means of an I travel of the saw frame substantially coin- Gident with the'completion of the kerf, or

emergence ofthe cutting'edge'of the saw from the lower surface of the Work; 7 M iA'furthe'r object of the invention is to provide forthe automatic return of the saw frame .to the up, or work-receiving position,

. atthe completion of the cutting operation.

7 Specification of Lette rs Patent.

7 v ris'Tow'EpL, citizen of the United 'fStatesJofAmeric'a,

During the downward of frame byflthe hand'o f the operator to bring I Figurelisa side elevation ofa machine 4 atented. Apr.--25, 1 922. Application filedlnec'ember 20, 19530; Se1' i;a1No. 43 I,'86d. i

of the type referredto showing. oneja'pplii cation of the invention, certain parts being i broken awa and the saw-frame being indi cated asin 1ts a ermidle position; v

Figure 2 1s a similar vlew showing the 30- about to be returned to startingp osition; 'Fi

of Fig. 3.

11's 5 sition of the'parts when the saw-frame is 1 re 3- is a'plan view partly'in section showlng the entire machine; and i The main frame 1 of the machine a V;-

-ing the latter.

"work support 2 comprising the relatively fixed clamping-jaw?) and a movable' cla' 'mp- AS herein disclosed; the 'fkbrk holding deflvic'e' is of a rtype-particularlyiadapted for' holding metal, but it is clear that'if the machine be intended forsawing woodfor simihereinillustrated. *A bracket 6. is secured serves to provide a ournalbearing forithe shaft for thesaw'driving wheel 11 rotating 'on'the upperendot such sha ftf Wheelll I:

has a saw engaging face lQandth'e bevel gear teeth "11*". The drive shaft 7 extends across the base throughabearing' bracket 6 ithin which a drive pulley 13 is arranged to be clutched bya clutch l4 to'sha'tt 7 -when worked by anyconvenient manually eperr r P la'r'material;suitableworkholding means Q j of usual-form may jbeisubstituted forthat y I ated shipper, as handle- 14, 131111 rod 14", bell crank 14? and sliding clutch-collar" Pr ma y i P i n Q me mg .1 :with the gear teeth 11? is keyed. toshaftfft to drive the wheel 11 whenever the clutch 14 is engaged.

Keyed to or integral with the sleeve? is a rigid arm 15 bifurcated at its outer extremity to form spaced imembers 16, 17.-

Secured in said members is rod or pin 18.

i The pivoted saw frame may be 'provi ded' with a spring motor cooperat ng with a-rigid arm on the saw fi'am'e'having' freely in'a slot atv the upper'end'of va veraau ovabl remar ed by theffspring;

A relatively heavy spring 'n'iay employed for raising the'rod to bgringthe lower-wall (sf-asset 1am arable warm. ween e part carried by the arm, to swing the,,f rame into its'up. o'r inoperative qsitip jrhe spr ng-actuated rod may, be. restored to its inoperative, original position, I without lafiecting thesaw frame, bymanualmeans such as a treadle having connectionsto; the lower endyof the rod. When in depressed-positi'on'the rod may be retained, by suitable 'latchrhavin en a ement witha )ortion of the. real 7 In the, lowest intended position ofithe frame, or afterthe passage of thesawco npletelythroughthe work, further motion; of the frame may be prevented by causing' the spring-motor to lift it. At latch releasing elemen'toperat'ed at a predetermined point oft-he motion of the trance may be rel'ied upon to release the energy stored in the w spring motor. to swing the saw frame into its up or inoperative position, thus: with:-

drawingthe saw, notifying theyoperator of the, completion of the work, and preventing damage to themachinevor saw."v 1 7 '1 rod 19,'fjor instance, is'arranged-toshde vertically through an opening 20 111" the ma- .chine i rame and through 'a cup=bracket 21 fast'upon theuppei surface of, the trainer 7 Atits up'per 'end therod l9 isslotted' at. 24

' thereof,

to provide a pair: of spaced parallel arms '22, 23. The pin or' rod: 18' passes through the slot 24' and; is freely, movable longitudinally At apoint below the-llower end of the ,s'lot'i l, the rod? :19 JIlS PIIO-VlClECl with a S, to take overthe collar'25, by a light spring 27. o The latch 29 is arranged to be released by means depending on the position of: the

1 frame 8, and, adapted for accurate ustnient. A'shackle 32 pivoted-at 33, for. in-

' stance, to the upper end otthe member 29,

is bored and threaded to receive a screw- 8 to a desiredmaximum: V 1 In -v operation, assuming I that the parts occupy the position, shownf in Fig-m1, J and Workto be out being insplace between the l threaded stop -rod 34 freely through wherein a similar shackle 37, and is provided with an; adjustable set-screw stop colhr 38 to take" against shackle, 37, which is pivotally mounted UP QHIIthB'IOClJUlY'PlH 1 8, The effective length of the stop rod may be adjustedroughly' by collar 38, and accurately by screwingirod 341 into and out of shackle- 32. A lock nut 36 is provided-to retain the adjusted positlon. mean-afar adjusting the effective position Obviously any of stop 38 will determine the point in the' be'releas edfromcollar 25. v I;

The spring26is compressed before start descent; of arm 15=at which the latch 29 will l V I ing; a cut} A lever 4 O,lh a-ving a tread-portion .41, is fixedly secured to the left-hand extremity of ajfrock shaft bearingsat 43, 44,0n the machineframe; The -shaft 42 has secured thereto a lever men be'r 45 bifurcated at its forwardextremity'to receive the lowerend of the rod '19 and bored 'for a pivot pin 47 connecting.thef rod and thelever member, 15-.-

The fame 8 may be partly counterbalanced by spring 19 secured to a suitable projection 5030f the frames, thelower end of -such springbeing connected to the machine frame at any desired point e a v In ordertocontrol the rate of movement of the frame S'dovvnward When released vfbyopo eration ofthe treadle dO'and rod 19-, or up a V ward'iwhen the spring 26'is' active, any suitr.

able .form of retarding or impeding device' may be provided to prevent too rapidino,-

1,8, is-extended on one side and reduced as shown to take into an eye 52 infthepistonrod 53 of afdash-potj50; In the preferred form shown,.this dash-p'ot-is va cast metal cylinder closed at the bottom and having bored; lugs 54:, for a, pin- 55 bearing in lugs 56 fast to frame 1. The piston 51: is without l packing, and the air leakage about it is such as to l mit the rate ofinotion jawsfi and'-4L, the operator-treads on'lever oi the frame 3-1 locks over coll-(11:25. Du'rin gsuch =move-' m'ent the fork 2'2, 23- of'rod 19' slidesdown ward relative to the pin 18' andlfmm'e' 8,

which the-operator hol dsup substantially in T the position/shownin Fig. 1 ,fojr allows, to

saw against the work; v Thefranie now 'acts by gravity of so much-0f frame 8 as isn'ot fallas restrained by dash-pot 50 to bring the a counterbalanced byspring 4 9 to feed the saw into the work and t he operator after ma ipulat-mg. the clutch handle 14: to start the saw, 7

may give his attention to: other duties while t-heimachine continues to operate: As arm 100 tionin either direction: Prefer'ably thejpin 3 11 5 40., 4-1, thus depressing therod'w and collar '25-, and compressing, s rin ee untihd'og 1 5. sweeps down-toward the position of Fig. 2, the shackle 37 approaches and finally contactswith the collar 88 on the rod 34 Any further downward movement of the saw frame swings the member 29 upon its pivot sufficiently to carrythe dog 3L out of engagement with the collar 25. ,The spring 26 is thus released to force the lower end ofthe' slot 24 into" engagement with the rod 18 and thereby through arm toswing the saw frameupwardly into the inoperative position indicated in Fig. 1. This, position indicates to the operator, without close attention,-that the machine has finished its '15 operation, and thus enables one operator to attend to several-machines or other work without waste of time.

WVhile the devices herein described are preQ ferred forms, minor variations for particu lar purposes will ojccurtothose skilledin the .art, without additional. disclosure, which might be adopted without departing from the invention. V

It will "beobserved that the automatic control of the operation of a power saw by the described. devices is secured by substantial, and durable machine elements without employing any elaborate mechanism, orany parts requiring to be made; to refined dimensions.

I claim z v 1. A metal cutting in a work-support, a ,cutter,1and means for driving the cutter, means for causing the cutter to approach the work on the worksupport andto' feed into the work; a springmotor and-connections thereto adapted to return the cutter to its, initial position, and means to'restrain the, springmotor from action adapted to be released at a predeter mined position of the cutter.

2. A metal cutting machine having thereporting said frame formovement toward and from the work-support, a springmotor for moving said frame away from the worksupport, and manually controllable devices for rendering said motor temporarily inoperative in a state of potential activity.

4. A metal cutting machine having a gravity actuated cutter frame, means for moving said frame in opposition to gravity,

machine having thereautomatically actuable devices for rendering said moving means operative to, so move-the frame upon completion, of aicut inithework of predetermined depth. 5. A metal sawing machine having a pivoted saw frame, a spring for mo-ving'isaid frame away from the work, means for plac 7 ing and holdingsaid spring undercomr' p'ression', and automatically actuable means for releasingsaid spring-at thecompletion of the sawing, operation whereby-"to:}move said frame and the saw away froml'thework. p 6. A metal cutting machine, comprising. in,

combination a Work-support, a framepivotally mounted'whereby to permit 'a cutter blade carried:itherebyyto be. moved toward suchwork-support, spring means; for swinging. said'frameawayfifrom" the work'.sup-' port, means :for. placing said spring under compression, and a retaining device .for maintaining said springunder compression during the operation of said cutter upon workheld in saidsupport -T 7. A ;metal cutting machine, comprising in; combination a-work-su'pp'ort, a frame piv- 9 0 otally mounted Wherebyto permit a cutter blade; carriedithereby to' be moved toward suchLwork-support, spring meansfOrsWingin}; said frame away'from' the work-support,

means for placing said spring. under com-J pression', anda retaining device for illitlIl-j; 1 taming said spring under c'ompressiondur:

ing the operation of said cutter upon work held in. said support, and. meansfor; re

tarding the swingingv motion offsaidframe'.

18. A metal-cutting machine having in combination a pivoted frame, aband saw carried thereby, means for driving the -saw,i-a worksupport, a spring-actuated abutment engageable with a part movablewlth said frame,

frame whereby to. lea-use saidabutment to movev said port;

to swing about an axis to feed the saw into the Work, an arm rigidly'secured to said' frame, a spring-motor operatively associated frame away"from' the-'work-'sup- Abandsaw machine having in combi-* L" nation a work-support, a saw frame'pivoted.

with said arm andadapted to move the lat-'--v terand thereby to swing said frame'away from the work-support, and a latch device for holding said spring-motor. inoperative,

during a predetermined extent r of operative feedingrnotionfiof the saw.

1i), tmctal cutting machinehavingdth erein a work-support,a frame movable toward and from thework-support, a cutter on the frame, and. means for driving the cutter, i n

combination with a spring-motor. for returning the frame to initial positioncomprising means having an abutment for driving enmeans for locking said abutment against movement,'and andevice for automatically disengaging said locl'ring'means at a'prede-.1 termined point -in1themotion, of the :saw

Y of said axle, an eccentric. abutment on the frame adapted to. contact-"with the rod, a

'gagement with a part carried by r the frame,

a spring adapted to be compressed in one position of said abutment, means for compressing the spring, a latch to holdthe abutment when the spring is compressed, and an adjustable connection between the frame and the latch-for releasing the latch at o W ne limit of: the mo'tionof the frame.

11 In a metal sawing machine of the bandsawingttype having a swinging saw frame adapted to move the-sawagainst the work by. gravitating, motion of the saw-frame .about'an axis, meansfor returning the saw frame to initialposition comprising a rod disposed for longitudinal motion at one side spring surrounding the'rod, means for; tensioning and holding under 5 tension said spring, and means for releasing saidfholding means when said frame attains one limitof' its swinging motion.

12. In a metal sawing machine of the band-' sawing type havinga swinging saw-frame adapted: to move-the saw against the work by ravitatingmotionof-the saw-frame about an axis, means for returning the saw frame Y 1303111111211 pos tion comprising a rod 'CllSPOSBd' for longitudinal motion at oneside of said axis, an eccentric abutment" on the frame adapted to contact with the rod, a spring surrounding the rod, means for tensioning and holding'under tension said'spring, and means for releasing said holding means when said fraine' attains one v limit of its swinging motion, in combination withlp'neumatic means for retarding the motion of said frame in each direction.

13. Ina machine of the class described,

combination a saw-frame pivotally supported'to swing under gravity about a substantially horizontal axis, an arm rigidly secured to-jsaid frame, a slidably: guided rod having a forked extremity for engaging a pin carried by said arm, a spring encircling said rodnndnormally tending to move saidrrod means for moving said frame -in one direction, amanually operable means for tensioning'saidspri'ng means, a latch -for 'holding T such means in-tensioned' condition, a connection extending from said latch, an abutment on saidyconnection adjustable toward andaway from the'latch, and means supported by'said' frame and adapted to engage. said abutment to move said latch wherebyto release said spring. 1

1 5. A machine of the class described havinga pivoted saw'frame and a spring for swinging saidframe to inoperative position, comp-rising in combination means for-com-" pressing saidspring,a pivoted latch for holding said spring under compression, an

adjustable ro'd secured tosaid latch, an abutment carried by said rod,:and a guide memher for the free end ofsaid rod, said-guide member being movable'with said frame and arranged for contact with said abutment whereby to move said latch to release said spring. 7 I f 16. In a machine of the class describedand having'a pivoted saw frame, in combination,

an arintast to said'frame, a rod guidedfor sliding movement and having an open 1 slot adja'centits eXtTemityQa collar'fast to said rod, a coil spring engaging below said collar whereby normally to-lift said rod, a pin secured: to' said arm" and seatedv within said open ended slot, and a tread'l'e device having connections to the *lowerjend of said rod wherebyvto depress the latterfand compress said spring.

setts, this seventeenth day of'D'ecember,1}920.'

. 'B'YRGN 1F4STOWELLI? 

